 On April 29th, a mile-long asteroid will make a close approach to Earth as it passes safely by. There's no need to worry, this asteroid will not even come close to hitting Earth. Our solar system is actually littered with asteroids and comets, and sometimes they do come very close to Earth. When an asteroid or comet could one day come close to our planet, it's known as a near-Earth object. But how close is close? A near-Earth object is defined as an object that could pass by our planet within 30 million miles. NASA begins to keep close watch on objects that could pass within 5 million miles of Earth. To put that in perspective, our Moon is only 238,900 miles away. Now, this doesn't mean that objects don't pass closer to us than our Moon. But the Moon is still very far away. However unlikely an impact is, NASA wants to know about all near-Earth objects so that we can track their movement through near-Earth space and predict their trajectories well into the future. The space agency has a planetary defense coordination office that maintains watch for asteroids and comets coming close to Earth in order to warn of any potential impacts. Along with its partners, they discover, catalogue and characterize these bodies. But what if one of these objects did pose a threat? If an asteroid were on a collision course with Earth, we want to be prepared. That's why NASA is working on several techniques and technologies to help deflect an asteroid on a collision course with Earth. Join us as NASA experts discuss April 29th's close approach and what NASA is doing every day to help protect our planet.